for me ive had bad experiences with dsp's as i feel the sound was not as strong as having it direct from the headunit, it was an alpine imprint box and the sound was softer, kinda like a bit more muffled, not just softer in db, no matter how i set the eq with or without the imprint box, it always sounded like the direct sound from headunit had not been pumped straight through the imprint box, like overly processed reminds me of the difference between same files in MP3 or FLAC format, the MP3 has had a slightly softer less impact to all the impact sounds and almost like an air sound induced throughout the track if you listen with headphones comparing it to the FLAC and WAV of same track. ANYTHING that adds stuff like this to my setup I avoid like Black Death.